Comparing SQL and NoSQL

Learn when to use SQL and when to use NoSQL.

Deciding which database to use#

The decision of which database to use depends on the data structure. If we have structured data, SQL is the way to go. However, if we have flexible or large amounts of data and need to deliver a real-time experience, NoSQL is the way to go.

Scalability and flexibility#

NoSQL databases are scalable and flexible and adhere to the BASE (Basic availability, Soft-state, Eventual consistency) consistency model. SQL is an excellent choice if the data is highly structured and ACID (Atomicity, Consistency, Isolation, and Durability) compliance is required. If the data is well-structured and organized, querying it with an SQL database is very efficient. Querying data in a NoSQL database is not as efficient as querying in a SQL database due to potential differences in the data structures. Databases can be scaled vertically or horizontally.

SQL databases are difficult to scale because they run on a single server to ensure data integrity. When we try to scale them, we must do so vertically.

NoSQL databases scale horizontally, and this makes scaling very easy. NoSQL contains objects that can be stored on multiple servers without being linked.

svg viewer

Structure#

We use NoSQL for large data sets, hierarchical data, and fast-growing businesses with no data structure. NoSQL is suitable for social networks, mobile apps, and streaming platforms. Facebook, Netflix, and Amazon, among others, use NoSQL databases. We use SQL databases when the data is small and well-structured, and we store this data in a tabular format.  It’s a good fit for small-scale e-commerce or transaction-processing systems. Microsoft and Accenture, among others, use SQL databases.

svg viewer

To summarize, the type of database we choose is dependent on our use case and plans. Therefore, before we decide on a database structure, it’s always best to thoroughly analyze what we want to build.

NoSQL use case#

If we’re working on a simple chat application and we want to scale it up and add features like private chats and groups, NoSQL should be our go-to database. That’s because of two key factors: scalability and concurrency. NoSQL is able to handle real-time activity and large amounts of data. Chatting is a real-time activity, and the data generated by multiple chats and other app activities may contribute to big data.

svg viewer

SQL use case#

If we’re working on a simple customer relationship management system to help us manage all of our company customers, an SQL database is our best bet. It has a much higher performance rate because customer data is linked, making it easy to alter and access the data.

svg viewer

Basics of Databases

Introduction to MongoDB